Steam-engine



(No Model.) 3 Sheets-Sheet 1.

B. BRAZELLE.

STEAM ENGINE. No. 245,775. Patented Aug. 16,1881,v

zizzesses:

N. PETERS. PMlo-Lfihognphan Washinzlun. Dv c.

3 Sheets-Sheet 2.

Patented Aug. 16,1881.

STEAM ENGINE.

B. BRAZELLE.

(No Model.)

,UNITED STATES PATENT OFFICE.

BENJAMIN BRAZELLE, OF ST. LOUIS, MISSOURI.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 245,775, dated August 16, 1881.

Application filed May '7, 1881. (No model.)

To all whom it may concern Be it known that I, BENJAMIN BRAZELLE, of St. Louis, in the county of St. Louis and State of Missouri, have invented certain new and useful Improvements in Steam-Engines, of which improvements the following is a specification.

My invention relates to means for effectively utilizing the expansion of steam, with a material simplification of mechanism relatively to the ordinary constructions of expansivelyworking engines; and to this end my improvements consist in the combination of a steamcylinder and stationary expansion-chambers, from which a regulated volume of steam is supplied at each stroke to the main distribution-valves of the engine; also, in the combination of an expansion-chamber with the head ot'the steam-cylinder; and, also, in the combination ofan expansion-chamber and adevice for varying the capacity of said chamber, and thereby correspondingly varying the degree of expansion, all as hereinafter more fully set forth.

In an application for Letters Patentof even date herewith, marked A, Ihave set forth an expansion-chamber formed within the body of the distribution-valve, and m y herein-described invention embodies the same fundamental principle ofdelivering a measured volume of steam from an expansion-chamber at each stroke of the piston, while differing substantially from that of my application above rel'erred to in the mechanical structure and combination of the devices employed.

In the accompanying drawings, Figure l is a longitudinal central section through the cylinder and steam-chest of an engine, the expansion-chambers being formed in the steam-chest and valves; Fl g2, atransverse section through the same at the line or as of Fig. 1, showing the application of a reducer; and Figs. 3 and 4, longitudinal central sections through steamengine cylinders having expansion-chambers formed in their heads.

.Myimprovements are herein shown as adapted to an engine having a single cylinder, A, which is of the ordinary construction, and is fitted with a piston, A, and piston-rod A Steam is supplied and exhausted either by a single main distribution-valve, B, as in Fig. 3,

or by a pair of valves, B B, as in Figs. 1, 2, and 4, no independent cut-off valve being employed or required? Referring to Figs. 1 and 2, a pair of vibrating or partially-rotating valves, B B, are fitted, one adjacent to each end of the cylinder, in suitable seats in the steam-chest B in which are formed induction and eduction passages b 1). Around and between the seats of the valves I form by prolongations of the walls of the steam-chest B two expansion-chambers, B B separated one from the other by a central partition, 12 which chambers are alternately filled with steam supplied through the induction-passage b, and emptied through the valves B into the cylinder. I have in this instance shown hollow valves, the interior of each of which forms a chamber which supplements the volume of the chest expansion-chamber within which it is located. The use of a chambered valve, which, as stated, is set forth in my application A, hereinbefore referred to,is not, however, an essential where the expansionchambers are formed in the chest, and I have herein embodied such valve for the purpose of exhibiting more clearly the means which I employ for altering the volume of the expansionchamber in order to vary thereby the degree of expansion. To this end I provide a series of reducers, O, of different dimensions, one of which, of proper size, I insert, through a removable bonnet, b' in the side of the steamchest, into each expansion-chamber or into each valve, as the case may be, when it is desired to work at a higher degree of expansion than that determined by the ratio of the volumes ot' the chamber and cylinder, or when steam of materially higher pressure is to be used. It will be obvious that the degree of expansion will be proportionally increased or the point of cut-off shortened, according as larger 01' smaller reducers are employed. The reducer may either be connected to the bonnet, as shown in Fig. 2, or may be made separate therefrom, so as to be insertible into the valve and to partake'of the movements thereof, the desired reduction of volume being produced in either case, and havingasimilar result, whether effected in a stationary or in a movable expansion-chamber.

Under certain circumstances it may not be being similar in both cases.

found desirable or practicable to increase the dimensions of the steam-chest by the addition of expansion-chambers thereto, and in such case, as for other reasons, the form of my improvements illustrated in Figs. 3 and 4 is of convenient and advantageous application. The expansion-chambers B are, under this construction, cylindrical receptacles, which are formed within the hollow cylinder-heads A and are each provided with a port, I), over which ports the distribution-valve travels, and through which the chambers are alternately filled with steam from the steam-chest and emptied into the cylinder, similarly to the expansion-chambers before described, and effectin g expansive action under a similar determining condition of relation of chamber and cylinder volume. The counterbore of the cylinder is preferably increased for the depth of the heads under their flanges, so as to form shoulders, against which their inner faces rest. A long D-slide, B, is shown in Fig. 3, and two vibrating valves, B, in Fig. 4, the relation of the valve to the chamber and cylinder port-s In the modification shown in Fig. 4 I provide the additional and important advantage of affording an efficient safeguard against breakage of the cylinder-heads due to excess of pressure or entrance of water into the cylinder. To this end 1 form the hollow cylinder-heads within which the expansion-chambers are located in two parts, the outer, A being circular plates fitting into the cylinder and secured, as usual, thereto, and the inner, A in which the ports I) are formed, cylinders which are open on their outer and closed on their inner ends, and of such depth that when in position against the shoulders of the counterbore their outer ends will stand clear of the adjacent faces of the outer plates, A so that free space is afforded to admit of their outward movement under the influence of an excessof internalpressure. Itwillbeobserved that in the normal working of the engine no tendency to such outward movement arises, as the pressure is equal on both sides of the inner plate during the receding stroke of the piston, and is greater on its outer than on its inner side durin gthe advancingstroke. When, however, an excess of outward pressure is induced, the inner section, A, yields, and by its outward movement relieves the undue strain, which might otherwise break the head.

I claim as my invention and desire to secure by Letters Patent- 1. A steanrchest for steam-engines having two internal expansion-chambers, each provided with a port adapted to establish communication alternately between the steam-pipe and the chamber and between the chamber and cylinder, substantially as set forth. 7

2. In a steam-engine, the combination, substantially as set forth, of a steam-cylinder, a distribution-valve, and a stationary expansionchamber, from which a regulated quantity of 6 5 steam is supplied to the distribution-valve at each stroke.

3. In a steam-engine, the combination, substantially as set forth, of a steam-cylinder and a steam-chest having internal expansion-chambers adapted to communicate alternately with the steam-supply pipe and with the cylinder.

4. ln a steam-engine, the combinatiom'sulr stantially as set forth, of a steam-cylinder, an expansion-chamber, and a reducer, whereby the volume of the expansion-chamber may be changed relatively to that of the cylinder.

5. In a steam-engine, the combination, substantially as set forth, of a steam-cylinder and a cylinder-head having an internal expansionchamber, with a port therein governed by a distribution-valve.

.6. In a steam-engine, the combination, substantially as set forth, of a steam-cylinder and a cylinder-head having an internal expansionchamber formed between a fixed outer plate and a movable inner cylinder having a port governed by the distribution-valve.

B. BRAZELLE. WVitnesses J. SNowDEN BELL, CHAS. A. SAFFoRD. 

